The present disclosure relates to a developing cartridge and a process unit.
In an example of an image forming apparatus such as a laser printer and the like, a drum cartridge holding a photosensitive drum is provided to be detachable in a main body case and a developing cartridge holding a developing roller is mounted on the drum cartridge. The drum cartridge and the developing cartridge mounted thereon together form a process unit.
A pressing mechanism for pressing the developing roller to the photosensitive drum is provided in the main body case. An engaging part is pressed part) is formed to protrude from the side wall of the developing cartridge. The pressing mechanism includes a pair of holding bodies sandwiching the engaging part therebetween and a biasing spring biasing one side of the holding bodies. One of the holding bodies is biased by the biasing spring and the engaging part is pressed by the holding body, such that the developing roller is pressed to the photosensitive drum.
In order to separate the developing roller from the photosensitive drum, a cam is provided in a state where a circumferential surface thereof contacts the other side of the holding bodies. According to a rotating position of the cam, the other of the holding bodies is pressed to one of the holding bodies and the engaging part is pressed by the other of the holding bodies. Accordingly, the developing cartridge moves against a biasing force of the biasing spring to separate the developing roller from the photosensitive drum.
When the developing roller does not rotate, the developing roller is separated from the photosensitive drum, such that it is possible to prevent deformation of the developing roller or the photosensitive drum.